This invention relates to an assembly for use in a procedure for implantation of an orthopaedic joint component.
US-A-2005/0197708 discloses a humeral component of a shoulder joint prosthesis which comprises a stem part, a head part, and a connector part which can be fitted into a bore in the head part, and has a bore formed in it to receive a spigot on the stem part. The eccentric arrangement of the bore in the head part relative to the axis of the head part, and the eccentric arrangement of the bore in the connector part eccentric relative to the axis of the connector part, allow the distance through which the head part is offset relative to the stem part, and the orientation of that offset, to be adjusted to suit the requirements of a patient. This can facilitate variation of effective arm length, and the extent of retroversion and anteversion.
It is important when assembling parts of a modular joint prosthesis component such as that disclosed in US-A-2005/0197708 to ensure that the parts are assembled securely, so that there is no possibility of relative movement between the parts.
The present invention provides an assembly for preparing a joint prosthesis component for implantation, which includes a tool on which the component can be placed, and which facilitates the application of an assembly force to the component.
Accordingly, in one aspect, the invention provides an assembly for use in a procedure for implantation of an orthopaedic joint component, which comprises:                a. a head part of the joint component which has a tapered bore within it,        b. a connector part which is tapered inwardly along its length so that it can be received snugly in the tapered bore in the head part, the connector part having a bore within it, and        c. an assembly tool which includes a spigot which fits snugly into the bore in the connector part,                    in which each of the tool and the connector part has a face which contact one another when the spigot on the tool is fully received in the bore in the connector part, and in which each of the said faces extends generally transverse relative to the aligned axes of the spigot and the bore.                        
In another aspect, the invention provides a method of assembling an orthopaedic joint component prior to implantation, which comprises:                a. providing a head part of the joint component and a connector part, in which the head part has a tapered bore within it in which the connector part can be received in a snug fit, and in which the connector part has a bore within it,        b. fitting the connector part into the bore in the head part,        c. placing the connector part on a tool which contacts a surface of the connector part which faces away from the head part, the tool having a spigot which is received in the bore in the connector part when the connector part is placed on the tool, and        d. applying force to the head part in a direction towards the connector part.        